Neurology Flashcards
Where in the CNS is CSF produced? Where is it absorbed?
Produced by choroid plexuses (mainly), ependymal cells of the ventricles, and arachnoidal membranes
Absorbed by arachnoidal villi
Which extraocular muscles are innervated by the oculomotor nerve?
Dorsal, ventral, and medial rectus
Also, parasympathetic nervous system to pupil (causes constriction)
Which peripheral nerve is involved in the perineal reflex arc?
Pudendal nerve
What is the primary neurotransmitter in skeletal muscle?
Acetylcholine
Damage to which area causes Horner’s syndrome? What are the clinical signs?
Cervical sympathetic trunk
Miosis, ptosis, enophthalmos, protrusion of the third eyelid
Summarize the innervation of the bladder.
Sympathetic innervation supplied by hypogastric nn (B2 receptors on detrusor mm cause relaxation/filling, a1 receptors on IUS cause contraction)
PS innervation by pelvic n, dominates during emptying phase/micturation
Somatic innervation by deep perineal nerve (branch of pudenal nerve) which allows for conscious control of EUS
Pontinue micturation center in brain is essential for complete emptying of the bladder
What is the main regulator of CSF pressure in a healthy individual?
Rate of CSF absorption by the arachnoidal villi (produced at a near constant rate)
A patient has the following signs: horizontal nystagmus with fast phase to the left, a right sided head tilt, and left-sided ataxia/CP deficits. What is the neuroanatomic localization?
Left side of the floculonodular lobe of the cerebellum (paradoxical vestibular disease)
What are the clinical signs of idiopathic head tremors?
Sudden onset of vertical and/or horizontal rhythmic head movements lasting from a few seconds to several hours, usually able to be distracted out of the episode
What are the clinical signs and signalment of cerebellitis (shaker syndrome)?
Sudden marked intention tremor of the head and limbs, which worsens with exercise, stress and excitement, but disappears during sleep; Classically seen in young, mature (<2 years), small white-breed dogs, particularly
Maltese terriers and West Highland white terriers, however, any breed can be affected
What is the clinical presentation for idiopathic trigeminal neuritis?
Dropped jaw (resulting from impaired muscles of mastification), trigeminal sensory deficits seen in 1/3 of dogs; concurrent facial nerve paralysis, Horner’s syndrome, or masticatory mm atrophy can occasionally be observed. Recover spontaneously in 2-4 weeks
Deficits to CN III cause what clinical signs?
Strabismus, mydriatic pupil (due to loss of PS innervation of eye)
What are the distinguishing characteristics of pre-ganglionic Horner’s syndrome from post-ganglionic Horner’s?
Pre-ganglionic: phenylephrine instilled in eye will have no effect on pupillary constriction (signifies injury to neck or brachial plexus)
Post-ganglionic: phenylephrine instilled in eye will cause pupillary dilation in ~20 minutes (most commonly due to otitis media/interna)
What are the two types of acetylcholine receptors?
Nicotinic and muscarinic
What are the clinical signs of cerebellar disease?
Normal behavior/alert, intention tremors, opisthotonous/extensor rigidity, exaggerated muscle tone/spinal reflexes, absent menace (ipsilateral)
